It's really simple, follow my instructions and you'll do it right!
1. You gotta download the hack, the link is given below.
MEGAUPLOAD - The leading online storage and file delivery service
VirusTotal - Free Online Virus, Malware and URL Scanner
2. Extract MW2v12208Hack.exe to your desktop
3. Open up MW2v12208Hack.exe
4. Open up Modern Warfare 2
5. The tab 'Multiplayer Trainer' and 'Rank/Prestige Editor' should be open
6. On the right, click on the prestige # you want
7. On the left, click on the rank # you want
8. Re-open MW2
NOTE: I do not take credit for this.
Just wanted to show you guys how to do it.